Cmm moving path adjustment assisting method and apparatus

ABSTRACT

A method is provided to assist adjustment for a movement path of a probe. A coordinate measuring machine includes a probe having a tip for detecting a surface of an object, and a movement mechanism for moving the probe, and measures a shape of the object by allowing the probe tip to scan the surface. A controller controls operation of the coordinate measuring machine by calculating a scanning path for allowing the probe tip to perform scanning movement and the movement path followed by the probe when the probe tip moves along the scanning path, setting control points on a line connecting each position of the probe tip and each corresponding position of the probe accepting a change in position of the control points by a user, and changing the movement path accordingly. A guide point allows the control points to move collectively.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 13/365,539, filed on Feb. 3, 2012, which claims the benefit ofpriority from U.S. Provisional Application No. 61/522,431, filed on Aug.11, 2011, both disclosures of which are expressly incorporated byreference herein in their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and an apparatus for settingand adjusting a movement path of a coordinate measuring machine thatmeasures the shape of a workpiece by scanning measurement.

2. Description of Related Art

A coordinate measuring machine that measures the shape of a workpiece byscanning measurement has been known.

FIG. 1 illustrates an exemplary configuration of a coordinate measuringsystem 10.

The coordinate measuring system 10 includes a coordinate measuringmachine 20 and a computer terminal 40.

The coordinate measuring machine 20 includes a surface plate 21, a probehead 22, and a movement mechanism 30. A workpiece W is placed on thesurface plate 21. The probe head 22 is used for scanning measurement ofthe workpiece W. The movement mechanism 30 allows the probe head 22 tothree-dimensionally move in X, Y, and Z directions.

As illustrated in FIG. 1, an X, Y, and Z Cartesian coordinate system isset as a coordinate system of the machine for ease of illustration.

The X-direction corresponds to the horizontal direction in FIG. 1. TheY-direction corresponds to a direction into and out of the plane ofFIG. 1. The Z-direction corresponds to the vertical direction in FIG. 1.

The movement mechanism 30 includes a gate-shaped frame 31, an X-slider33, Z-axis spindle 34, and a drive mechanism (not shown).

The gate-shaped frame 31 includes a cross beam 32 which is laid in theX-axis direction. The gate-shaped frame 31 is provided movably in theY-axis direction.

The X-slider 33 includes a column having a length in the Z-axisdirection. The X-slider 33 is provided slidably in the X-axis directionalong the cross beam 32.

The Z-axis spindle 34 is inserted into the X-slider 33, and is providedslidably in the Z-axis direction.

The drive mechanism (not shown) includes a motor for driving thcgate-shaped frame 31, the X-slider 33, and the Z-axis spindle 34 in therespective axis directions.

Assume herein that the shape of the workpiece W with turbine bladesillustrated in FIG. 2 is measured by scanning measurement, for example.

The workpiece W has a structure in which a plurality of blades WB ismounted in parallel on a side surface of a main body WM. Assume hereinthat scanning measurement is performed to check if the shape of eachblade WB is finished in conformity with designed values.

When a user sets a section S to be measured while viewing a screen 41 ofthe computer terminal 40, the computer 40 works out a scanning path SRbased on the designed values of the workpiece W.

A contacting sphere 27 of the probe head 22 is moved along the scanningpath SR to scan coordinates with a predetermined measurement pitch.

The term “scanning path SR” herein described refers to a path along thesurface of the workpiece W to be measured.

The contacting sphere 27 is moved along scanning path SR to therebyperform scanning measurement.

In order to move the contacting sphere 27 along the scanning path SR, itis necessary to appropriately move the probe head 22 according to thescanning path SR.

As illustrated in FIG. 3, a movement path MP of the probe head 22 istemporarily determined based on the scanning path SR and is displayed onthe display screen 41, so that the user can confirm the movement path MPof the probe head 22 on the screen 41.

The “position of the probe head 22” corresponds to “a predeterminedrepresentative point within the probe head”. Examples of such arepresentative point include an uppermost point (a junction point with alowermost end of the Z-axis spindle) of the probe head 22, a rotationcenter of the probe head 22, and an intersection of two rotation axes tobe described later. Any point may be used as the representative point aslong as it can represent the position of the probe head 22.

If the probe head 22 has a rotary joint or a swing joint, a joint point(a connection point between relatively movable members) of the rotaryjoint or the swing joint may be set as the representative point of theprobe head 22.

The movement path MP which is automatically calculated by the computerterminal 40 according to the scanning path SR of the contacting sphere27 is not appropriate in many cases.

For example, as illustrated in FIG. 4, assume that the movement path MPof the probe head 22 is generated so that the probe head 22 ispositioned in the simplest manner in a direction perpendicular to thesection S to be measured. In this case, a stylus 26 maintains a postureparallel with the Z-axis. As a result, the stylus 26 collides with theblades WB. Now, attention is turned to a region 900 which is surroundedby a dashed line in FIG. 4.

To avoid the collision mentioned above, when the stylus 26 is laid downto be in parallel with an XY plane, the stylus 26 and the probe head 22may collide with a neighboring blade.

Accordingly, it is necessary for the user to make an adjustment so as toobtain an appropriate movement path for the probe head 22.

SUMMARY OF THE INVENTION

Herein, control points CP are prepared to facilitate the adjustment.

The control points CP are set on a line connecting each position of thecontacting sphere 27 on the scanning path SR and each position of theprobe head 22 corresponding to each position of the contacting sphere27.

The position of the probe head 22 can be changed by moving the positionof each control point CP.

Not only the position of the probe head 22, but also the posture of thestylus 26 can be adjusted by changing the position of the probe head 22.

As a result, an optimum movement path MP for the probe head 22 can begenerated so as to prevent the stylus 26 and the probe head 22 frominterfering with the workpiece W upon measurement and to minimize amovement amount and an operation amount (a rotation operation or thelike) of the probe head 22, for example.

In order to move the position of each control point CP, the controlpoint CP whose position to be changed is selected by moving a mousecursor while viewing the display screen 41.

Then, coordinate values indicating the position to be changed are inputby pressing keys on the display screen 41, to thereby change theposition of each control point CP (see FIG. 5).

Each control point (control point) CP contains information forcontrolling the measurement operation, such as coordinates of eachmeasurement point on a workpiece, a normal line for a workpiece surfaceat each measurement point, a stylus posture for approaching eachmeasurement point, a scan speed, and a measurement pitch.

The host computer 40 controls the operation of the coordinate measuringmachine 20 using the information associated with the control points CP.

Each control point CP is displayed on the display screen 41, and theposition of each control point CP can be manually changed by the user.This enables adjustment of an optimum movement path MP for measurement.

However, the operation of manually inputting each coordinate positionand moving the control points CP one by one is troublesome. Furthermore,when the coordinate positions of each control points CP are manuallyinputted one by one, the movement path MP is formed into a zigzag shape,which makes it difficult for the probe to move smoothly.

Under such circumstances, considerable time and labor have been requiredfor measurement of the workpiece shape.

A first exemplary aspect of the present invention is a CMM moving pathadjustment assisting method that assists adjustment for a movement pathof a probe in a coordinate measuring system, the coordinate measuringsystem including: a coordinate measuring machine that includes the probehaving a probe tip at a tip thereof for detecting a surface of an objectto be measured, and a movement mechanism for moving the probe, andmeasures a shape of the object to be measured by allowing the probe tipto scan the surface of the object to be measured; and a controller thatcontrols operation of the coordinate measuring machine, the methodincluding: calculating, by the controller, a scanning path for allowingthe probe tip to perform scanning movement along the surface of theobject to be measured; calculating, by the controller, the movement pathfollowed by the probe when the probe tip moves along the scanning path;setting, by the controller, control points on a line connecting eachposition of the probe tip on the scanning path and each position of theprobe corresponding to each position of the probe tip; and accepting, bythe controller, a change in position of the control points by a user,and changing the movement path according to the change in position ofthe control points. Further, the controller provides adjustment guidemeans for allowing a plurality of control points to move collectively.

Further, upon accepting a drag operation by a user to point a mousecursor to each control point on a display screen, the controller changesa position of each control point subjected to the drag operation to aposition designated by the drag operation.

The above and other objects, features and advantages of the presentinvention will become more fully understood from the detaileddescription given hereinbelow and the accompanying drawings which aregiven by way of illustration only, and thus are not to be considered aslimiting the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an exemplary configuration of acoordinate measuring system;

FIG. 2 is an enlarged view of an object to be measured;

FIG. 3 illustrates a scanning path SR and a movement path MP of a probehead 22 corresponding to the scanning path SR;

FIG. 4 is a partial enlarged view of FIG. 3;

FIG. 5 illustrates a state where positions of control points CP arechanged;

FIG. 6 is an enlarged view of the probe head;

FIG. 7 illustrates an example of a screen for setting measurementconditions;

FIG. 8 illustrates an example of a screen for setting adjustment guidemeans;

FIG. 9 illustrates a scanning path SR of a contacting sphere, a movementpath MP of a probe head corresponding to the scanning path SR, and alayout of control points CP corresponding to the scanning path SR andthe movement path MP;

FIG. 10 is an enlarged view illustrating a periphery of the controlpoints CP and guide operation means;

FIG. 11 is another enlarged view illustrating a periphery of the controlpoints CP and the guide operation means;

FIG. 12 illustrates a state where a guide curve GC is expanded;

FIG. 13 is an enlarged view illustrating a vicinity of a scanning path;

FIG. 14 illustrates a state where the guide curve GC is moved in anX-axis direction;

FIG. 15 illustrates a state where the guide curve GC is rotated about aZ-axis;

FIG. 16 illustrates a state where the control points CP are moved by adrag operation of a mouse cursor;

FIG. 17 illustrates a workpiece with holes;

FIG. 18 illustrates an example of a screen for setting the adjustmentguide means;

FIG. 19 illustrates the scanning path SR, the movement path MP of theprobe head 22, and a layout of the control points CP;

FIG. 20 illustrates an example of the movement path MP of the probe head22;

FIG. 21 illustrates a state where the guide point GP is moved in theX-axis direction;

FIG. 22 illustrates a workpiece having a flat surface;

FIG. 23 illustrates an example of a screen for setting the adjustmentguide means;

FIG. 24 illustrates the scanning path SR, the movement path MP of theprobe head 22, and a layout of the control points CP;

FIG. 25 illustrates a state where the interval between control points atboth ends is increased;

FIG. 26 illustrates a state where the interval between control points atboth ends is reduced;

FIG. 27 illustrates a state where a guide line GL is moved in parallel;and

FIG. 28 illustrates an example of a horizontal shape measurementapparatus.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Hereinafter, embodiments of the present invention are illustrated anddescribed with reference to reference symbols given to the constituentelements in the drawings.

First Embodiment

A first embodiment of the present invention will be described.

In the present invention, a coordinate measuring machine performsscanning measurement to measure the shape of a workpiece. The structureof the coordinate measuring machine itself has been conventionallyknown. The present invention can be applied to a coordinate measuringmachine 20 described in the “BACKGROUND OF THE INVENTION” section, andalso to other well-known three-dimensional coordinate measuringmachines.

Referring next to FIG. 6, a probe head 22 will be described.

The probe head 22 is mounted at a lower end of the Z-axis spindle 34.The probe head 22 includes a rotary joint 24, a swing joint 25, and astylus 26. An upper movable portion of the rotary joint 24 is mounted ata lower end of the Z-axis spindle 34, and a lower movable portion of therotary joint 24 is mounted on the swing joint 25.

Herein the rotary joint 24 rotates about an axis parallel with theZ-axis. The swing joint 25 is swingable about an axis perpendicular tothe Z-axis.

The stylus 26 is supported at a lower end of the swing joint 25.

A contacting sphere 27 is provided at a tip of the stylus 26.

Each of the rotary joint 24 and the swing joint 25 is driven by a motor.

Accordingly, the coordinate measuring machine 20 allows the contactingsphere 27 to move in five axis directions, i.e., the X-axis direction,the Y-axis direction, the Z-axis direction, a direction about theZ-axis, and a direction about an axis perpendicular to the Z-axis.

Thus, the coordinate measuring machine 20 has a function for allowingthe contacting sphere 27 to move in five axis directions. This makes itpossible to approach any workpiece surface by controlling both therotary joint 24 and the swing joint 25 to be rotationally drivensimultaneously, without the need for replacing the probe head 22 orchanging a workpiece posture even when the workpiece has a complexshape. Consequently, the measurement efficiency can be drasticallyimproved.

A feature of this embodiment is to provide adjustment guide means forappropriately moving each control point CP with a simple and quickmanipulation upon manual adjustment to appropriately adjust a movementpath MP of the probe head 22.

Hereinafter, the adjustment guide means will be described using aspecific measurement example.

The workpiece described in the “BACKGROUND OF THE INVENTION” section isused as a workpiece W to be measured according to this embodiment.Specifically, as illustrated in FIG. 2, scanning measurement isperformed on contour shapes of blades WB which are mounted on a sidesurface of a main body WM in parallel.

As illustrated in FIG. 2, a contour to be measured is designated bysetting a section S to be measured.

Further, measurement conditions are set.

FIG. 7 illustrates an example of a screen for setting measurementconditions.

As illustrated in FIG. 7, a scan speed (D51) and a scan pitch (D52) areset.

The term “scan pitch (D52)” refers to a degree of fineness ofmeasurement point sampling on a workpiece surface.

Further, the fineness of setting for control points CP is set (D53).

This embodiment illustrates a configuration example in which the controlpoints CP are generated every time the curvature of a scanning path SRof the contacting sphere 27 reaches 30 degrees, or every 5 mm along thescanning path SR of the contacting sphere 27.

FIG. 7 includes a field (D54) for setting a probe head direction. Inthis field, an angle of the probe to approach a workpiece surface can beset, for example.

FIG. 8 illustrates an example of a screen for setting the adjustmentguide means.

This embodiment illustrates an example in which “Guide curve” isselected as the adjustment guide means (D55).

In this embodiment, since the contour shape of the outer surface of theworkpiece is measured, the guide curve GC is suitably used as theadjustment guide means.

In addition to the guide curve, a guide point GP and a guide line GL,which will be described later by way of other embodiments, are alsoprepared as examples of the adjustment guide means.

In addition, necessary conditions, such as a data sampling pitch, areset.

After the settings as described above, “Settings for Spacing CP” buttonis clicked (D56).

As a result, as illustrated in FIG. 9, the scanning path SR of thecontacting sphere 27 and the movement path MP of the probe head 22corresponding to the scanning path SR are generated, and the controlpoints CP corresponding to the scanning path SR and the movement path MPare further generated to be arranged.

As described in the “BACKGROUND OF THE INVENTION” section, the controlpoints CP are set on a line connecting each position of the contactingsphere 27 on the scanning path SR and each position of the probe head 22corresponding to each position of the contacting sphere 27.

Further, as illustrated in 4, the stylus 26 collides with the blades WBif the movement path MP automatically calculated by a host computer 40is not appropriate, and it is necessary for a user to perform anadjustment operation to move each control point CP so that the movementpath MP of the probe head 22 can be appropriately set.

In this embodiment, the guide curve GC serving as adjustment guide means100 and guide operation means (3D Handle) 200 for operating the guidecurve GC are prepared to facilitate the operation for adjusting theposition of each control point upon execution of the adjustmentoperation for the user to move each control point CP.

FIG. 10 is an enlarged view illustrating a periphery of the controlpoints CP and guide operation means 100.

The guide curve GC is a curve obtained by smoothing all the controlpoints CP, and all the control points CP are set on the guide curve GC.

Accordingly, the control points CP are collectively moved together withthe guide curve GC by scaling the “guide curve GC” with respect to thecenter of the guide curve GC.

All the control points CP set on one guide curve GC are typically formedon a single plane depending on the contour of the workpiece W to bemeasured or the scanning path SR. Accordingly, all the control pointsneed not be formed on a single plane as illustrated in FIG. 11.

The guide curve GC typically has an oval or circular shape depending onthe contour of the workpiece W to be measured and the scanning path SR,but the shape of the guide curve GC is not limited to an oval orcircular shape.

The guide curve GC may be a curve that connects the control points CP ina ring shape, but the shape of the curve is not limited to a closedannular shape. Alternatively, a single continuous curve having an openedshape may be used.

The guide operation means (3D Handle) 200 is provided with a scale box210, a drag ball 220, a drag axis 230, and a rotating ring 240.

The scale box 210 is an operation icon for scaling up and down the guidecurve GC with respect to the center of the guide curve GC.

For example, when the scale box 210 is operated to be scaled up on thedisplay screen, the guide curve GC is also expanded accordingly.

Further, when the scale box 210 is operated to be scaled down, the guidecurve GC is reduced accordingly.

The operation for scaling up and down the scale box 210 can be performedby any method, as long as the operation can be carried out withoutgiving a sense of discomfort to the user.

For example, an operation method may be set in which the scale box 210is scaled down by a drag operation to move an angle toward the center ofthe scale box 210 in the state where the mouse cursor is pointed to theangle of the scale box 210.

When the guide curve GC is expanded using the scale box from the stateillustrated in FIG. 10, the state illustrated in FIG. 12 is obtained,for example.

Along with the expansion of the guide curve GC, all the control pointsCP are moved.

Referring to FIG. 10, the stylus 26 is constantly parallel with theZ-axis, so that the stylus 26 collides with the workpiece W (see FIG.4). Referring to FIG. 12, the movement path MP of the probe head 22 islarger than the scanning path SR. Thus, the stylus 26 approaches eachmeasurement point at a slightly oblique angle.

This adjustment avoids interference between the stylus 26 and theworkpiece W as illustrated in the enlarged view of FIG. 13.

Conventionally, it is necessary to adjust the movement path MP of theprobe head 22 by manually inputting each position of control points tobe moved.

In this embodiment, only a simple operation of slightly expanding theguide curve GC using the scale box 210 allows the positions of allcontrol points to he appropriately moved at the same time. Since all thecontrol points CP are set on the guide curve GC, all the control pointsCP are set on a single smooth curve. Accordingly, the movement path MPof the probe head 22 is also smooth, so that the smooth and optimummovement path MP of the probe head 22 can be obtained without a slightadjustment of the position of each control point CP.

The drag ball 220 is an operation icon for moving the guide curve. Thedrag ball 220 allows the guide curve GC to move in any direction in athree-dimensional space.

The drag ball 220 may be located at the center of the guide curve GC,for example, on the display screen 41.

As is obvious from FIG. 11, the drag ball 220 is disposed at a positioncorresponding to a substantial center of the guide curve GC, though thismay be somewhat difficult to see in FIG. 10 in which the control pointsoverlap each other.

The drag ball 220 is movable in parallel with the X-axis, Y-axis, orZ-axis, and is also movable to a midpoint between the X-axis and theY-axis, for example, irrespective of the axis directions of thecoordinate system.

The drag axis 230 is an operation icon for moving the guide curve GC inthe X-axis direction, Y-axis direction, or Z-axis direction.

The drag axis 230 is provided with an X-axis direction arrow 230 x, aY-axis direction arrow 230 y, and a Z-axis direction arrow 230 z.

For example, when the X-axis direction arrow 230 x is selected anddragged by the mouse cursor, the guide curve GC can be moved in thedirection along the X-axis.

The X-axis, Y-axis, and Z-axis directions herein described are definedin a workpiece coordinate system, for example. Alternatively, a machinecoordinate system may be used, and thus the user may select one of thesesystems.

When the guide curve GC is moved in the X-axis direction using the dragball 220 or the X-axis direction arrow 230 x from the state illustratedin FIG. 12, the state illustrated in FIG. 14 is obtained, for example.

A position where the stylus 25 does not interfere with the neighboringblade WB may be determined by shifting the position of the guide curveGC to right or left.

Also in this case, all the control points CP are simultaneously movedalong with the movement of the guide curve GC, so that the operation isextremely simplified.

The rotating ring 240 is an operation icon for rotationally moving theguide curve GC. Examples of the rotation operation include a rotationabout the X-axis, a rotation about the Y-axis, and a rotation about theZ-axis. Accordingly, as illustrated in FIG. 11, an X-axis rotation icon240 x, a Y-axis rotation icon 240 y, and a Z-axis rotation icon 240 zmay be provided around the respective axes. Alternatively, when only arotation about the Z-axis is allowed, for example, due to thelimitations of the scanning path SR and the movement path MP, only theZ-axis rotation icon 240 z may be displayed as illustrated in FIG. 12.

When the guide curve GC is rotated about the Z-axis from the stateillustrated in FIG. 12 by using the Z-axis rotation icon 240 z, thestate illustrated in FIG. 15 is obtained, for example.

Also in this case, all the control points CP are simultaneously movedalong with the movement of the guide curve GC, so that the operation isextremely simplified.

In the operation examples described above, the operation for allowingall the control points to be moved simultaneously using the guideoperation means (3D Handle) 200 has been described.

Herein, the positions of the control points CP may be individually movedto make a final slight adjustment.

In this embodiment, upon movement of the respective positions of thecontrol points CP, each control point CP can be moved to a desiredposition on the display screen by selecting and dragging the controlpoint CP by the mouse cursor 42 as illustrated in FIG. 16.

An operation (GUI) using such a pointing device is more intuitive andsimpler than a conventional command-based operation such as an input ofcoordinates. This contributes to simplification and improvement inefficiency of a measurement operation.

Modified Example

Although the above embodiment illustrates a guide curve that connectsall control points, the guide curve need not connect all control points.Alternatively, a virtual curve that smoothly connects three or morecontrol points selected by a user, for example, may be used as a guidecurve.

In this case, assuming that the user selects and drags one of thecontrol points connected by the guide curve, non-selected control pointsare also moved so that the control points are connected by a smoothcurve such as a spline curve. This simplifies the adjustment of themovement path, and allows the user to selectively adjust only desiredcontrol points.

Second Embodiment

Next, a second embodiment of the present invention will be described.

While the basic structure of the second embodiment is the same as thatof the first embodiment, a guide point will be described in the secondembodiment as an example of the adjustment guide means.

Since the first embodiment illustrates measurement of a contour shape ofa workpiece outer surface, a guide curve is suitably used as theadjustment guide means.

Herein, in the case where an inner diameter of each hole WH in theworkpiece W is measured as illustrated in FIG. 17, for example, a guidepoint is used as the guide adjustment means.

The inner diameter of each hole illustrated in FIG. 17 is designated asa measurement target.

Then, “Guide point” is selected as the adjustment guide means on thesetting screen illustrated in FIG. 18, and the “Settings for Spacing CP”button is clicked (D56). As a result, the movement path MP of the probehead 22 and the control points CP corresponding to the scanning path SRare arranged on the display screen as illustrated in FIG. 19.

Herein, the position of the probe head 22 is not moved, and thecontacting sphere 27 is allowed to scan-move along the inner diameter ofthe hole WH by the operation of each of the swing joint 25 and therotary joint 24, so that the movement path MP corresponds to “onepoint”.

As illustrated in FIG. 20, the probe head 22 may be moved also in thescanning measurement of the inner diameter of the hole WH.

The guide point GP may correspond to one point where the control pointsCP are concentrated.

The scanning path SR has a circular shape, so that the movement path MPalso has a circular shape.

Accordingly, the control points CP are arranged in a circular shape. Allthe control points are concentrated on the center point of the circle oron one point on an axial line passing through the central axis of thecircle. As a result, all the control points are collectively moved alongwith a movement of the point.

When the movement path corresponds to “one point” as illustrated in FIG.19, the control points CP may be concentrated on the one point. Then,the guide point GP is disposed at a position corresponding to the onepoint. Accordingly, referring to FIG. 19, the guide point GP matches the“point” of the movement path MP. Further referring to FIGS. 19 and 20,the guide point and the control point overlap and appear as one point.

As with the first embodiment, the guide operation means 200 is providedto move the position of the guide point GP. In the second embodiment,the drag ball 220 and the drag axis 230 are provided, but the scale boxand the rotating ring are not provided due to limitations on the degreeof freedom of movement (change) of the guide point GP.

Since the drag ball 220 is disposed at the center of the control pointgroup, the drag ball 22 overlaps the control points as illustrated inFIGS. 19 and 20.

Referring to FIG. 19, the guide point GP, the “point” of the movementpath MP, and the drag ball 220 overlap each other.

In the actual measurement of a hole diameter, scanning may be performedby bringing the probe head 22 closer to the workpiece W, or by bringingthe probe head 22 away from the workpiece W.

Otherwise, the probe head 22 may approach a hole from a slightly obliquedirection with respect to the central axis of the hole.

In such cases, the movement path MP of the probe head 22 is collectivelymoved along with a movement of the drag ball 220 on the display screen.

In the case of FIG. 19, the position of the probe head 22 is moved.

FIG. 21 illustrates a case where the guide point GP is moved in theX-axis direction using the drag ball or the drag axis from the stateillustrated in FIG. 19.

In the conventional operation, a number of control points CP arearranged even in the case of measuring a hole diameter. The operation ofshifting the positions of these control points CP one by one by manualinput is troublesome.

In this regard, the use of the guide point GP of this embodiment allowsthe control points CP to be collectively moved at one time, so that theoperation is extremely simplified.

Third Embodiment

Next, a third embodiment of the present invention will be described.

While the basic structure of the third embodiment is the same as that ofeach of the first and second embodiments, a guide line BL will bedescribed as an example of the adjustment guide means in the thirdembodiment.

In the third embodiment, as illustrated in FIG. 22, assume thatmeasurement is performed along a predetermined straight line on a flatouter surface of a workpiece.

In this case, the guide line GL is used as the adjustment guide means.

A line L illustrated in FIG. 22 is designated as a measurement target.

In the setting screen illustrated in FIG. 23, “Guide line” is selectedas the adjustment guide means (D58), and “Settings for Spacing CP”button is clicked (D56).

As a result, the movement path MP of the probe head 22 and the controlpoints CP corresponding to the scanning path SR are arranged on thedisplay screen as illustrated in FIG. 24.

Referring to FIG. 24, the scanning path SR is a straight line, and themovement path MP of the probe head 22 is also a straight line.

Accordingly, the control points CP may be aligned on a straight line.

Herein, the guide line GL corresponds to the line connecting the controlpoints CP at both ends.

A display of the control points CP is omitted except for control pointsat both ends, and only the guide line GL is displayed.

As with the first embodiment, the guide operation means 200 is providedto move the position of the guide line GL. In the third embodiment, thedrag ball 220, the drag axis 230, the scale box 210, and the rotatingring 240 are arranged.

In this case, however, the rotating ring 240 is allowed to rotate onlyabout an axis parallel with the guide line GL due to limitations on thedegree of freedom of movement of the guide line GL.

The drag ball 220 is disposed at a midpoint between control points atboth ends.

As operation examples, FIG. 25 illustrates an example where the guideline GL is expanded using the scale box 210, and FIG. 26 illustrates anexample where the guide line GL is reduced using the scale box 210.

Along with expansion or reduction of the interval between the controlpoints CP at both ends, all the control points CP are simultaneouslymoved and the movement path MP is expanded or reduced.

FIG. 27 illustrates an example where the guide line GL is moved inparallel using the drag ball 220 or the drag axis 230 from the stateillustrated in FIG. 25.

Also in this case, the positions of all the control points CP arechanged together with the guide line GL.

Modified Example

Also in the case of using the guide line GL, three or more controlpoints CP selected by the user, or the selected control points CP andsome other control points CP around the selected control points may bemoved to generate the guide line GL.

The present invention is not limited to the above embodiments, but maybe modified in various manners without departing from the scope of thepresent invention.

An appropriate addition may be made in consideration of the usability ofeach user. For example, the size of an icon may be appropriately changedso as to easily recognize selected guide operation means when one of theguide operation means is selected by a mouse cursor.

Although a contact probe is used by way of example in the aboveembodiments, the present invention can also be applied to a non-contactscanning probe.

The above embodiments exemplify a mode in which the movement mechanism30 of the coordinate measuring machine 20 includes the gate-shaped frame31. However, the configuration of the coordinate measuring machine isnot limited to the above embodiments, as long as the coordinatemeasuring machine has a function for allowing a probe to move along thesurface of a workpiece.

A shape measurement apparatus shown in FIG. 28 is illustrated by way ofexample.

The shape measurement apparatus illustrated in FIG. 28 in udes twothree-dimensional coordinate measuring machines CMM1 and CMM2. The twothree-dimensional coordinate measuring machines CMM1 and CMM2 areopposed to each other with the object to be measured W interposedtherebetween.

The three-dimensional coordinate measuring machine CMM1 is provided witha spindle 34A, a probe 22A, a driving device 30A, and a controller 40A.The probe 22A is mounted at a tip of the spindle 34A. The driving device30A drives the spindle 34A and the probe 22A. The controller 40Aperforms movement control for measurement.

Similarly, the three-dimensional coordinate measuring machine CMM2 isprovided with a spindle 34B, a probe 22B, a driving device 30B, and acontroller 40B. The probe 22B is mounted at a tip of the spindle 34B.The driving device 30B drives the spindle 34B and the probe 22B. Thecontroller 40B performs movement control for measurement.

The spindles 34A and 34B are provided in the horizontal directionY-direction), and are respectively supported by columns 31A and 31B eachhaving a height in the Z-direction.

The spindles 34A and 34B are movable vertically along the columns 31Aand 31B, and are slidable in the horizontal direction with respect tothe columns 31A and 31B.

Accordingly, the present invention can also be applied if the spindles31A and 34B are provided in the horizontal direction.

Herein, since the two three-dimensional coordinate measuring machinesCMM1 and CMM2 are installed, the controller 40A connected to thethree-dimensional coordinate measuring machine CMM1 and the controller40B connected to the three-dimensional coordinate measuring machine CMM2are connected together by wired or wireless linking means for allowingthe controllers to be linked together. The two controllers 40A and 40Bperform control in collaboration with each other, thereby achievingmovement control for the overall shape measurement apparatus.

Instead of installing the two three-dimensional coordinate measuringmachines, only one of the three-dimensional coordinate measuring machineCMM1 and the three-dimensional coordinate measuring machine CMM2 may beinstalled.

The disclosure of U.S. Pat. No. 7,971,365 (date of patent: Jul. 5, 2011)is incorporated in this application in its entirety by reference.

From the invention thus described, it will be obvious that theembodiments of the invention may be varied in many ways. Such variationsare not to be regarded as a departure from the spirit and scope of theinvention, and all such modifications as would be obvious to one skilledin the art are intended for inclusion within the scope of the followingclaims.

What is claimed is:
 1. A CMM moving path adjustment assisting methodthat assists adjustment for a movement path of a probe in a coordinatemeasuring system, the coordinate measuring system including: acoordinate measuring machine that includes the probe having a probe tipat a tip thereof for detecting a surface of an object to be measured,and a movement mechanism for moving the probe, and measures a shape ofthe object to be measured by allowing the probe tip to scan the surfaceof the object to be measured; and a controller that controls operationof the coordinate measuring machine, the method comprising: calculating,by the controller, a scanning path for allowing the probe tip to performscanning movement along the surface of the object to be measured;calculating, by the controller, the movement path followed by the probewhen the probe tip moves along the scanning path; setting, by thecontroller, control points on a line connecting each position of theprobe tip on the scanning path and each position of the probecorresponding to each position of the probe tip; and accepting, by thecontroller, a change in position of the control points by a user, andchanging the movement path according to the change in position of thecontrol points, wherein the controller provides a guide point forallowing a plurality of control points to move collectively, wherein allthe control points are concentrated on one said guide point, and whereinupon receiving an input for operating the one said guide point, thecontroller causes all the control points to move collectively accordingto a movement of the one said guide point.